1. Field of the Invention
The present invention relates to a device for locking a shift lever of an automatic transmission which is capable of inhibiting movement of the shift lever from a non-driving position such as neutral or parking position under a certain condition.
2. Description of the Related Art
When parking an automobile with an automatic transmission, it is a common practice to set the automobile in an immobile state by actuating a parking brake and setting the automatic transmission shift lever at a P (parking) position before leaving the automobile.
When re-starting the automobile, the driver starts the engine while the lever is still in the P position and then moves the shift lever to a D (driving) position past an R (reversing) position. The driver, therefore, has to keep the foot brake engaged during shifting from the P position to the D position, in order to prevent the automobile from moving in reverse.
Usually, the motion of the shift lever is interlocked with various other functions. For instance, an interlocking mechanism is employed in which the motion of the shift lever is interlocked with the state of a steering locking mechanism in such a manner that the movement of the shift lever from a non-driving position such as the P position or an N (neutral) position is prevented under a certain condition of the steering lock. Such an interlocking mechanism is operatively connected to a detent pin which is movable between an inoperative position and an operative position when a button on the knob of the lever is pressed and released respectively by the driver. The operation of this button tends to be impaired due to the presence of the interlocking mechanism which is connected to the detent pin. It has also been experienced that the operation of the interlocking mechanism is inconveniently influenced by the manual pressing force exerted on the button on the shift lever knob.